How to fix "zsh: command not found: python" error? (macOS Monterey 12.3, python 3.10, Atom IDE, atom-python-run 0.9.7)

Question

Since I got Monterey 12.3 update (not sure it's related though), I have been getting this error when I try to run my python code in the terminal:

I am using python 3.10.3, Atom IDE, and run the code in terminal via atom-python-run package (which used to work perfectly fine). The settings for the package go like this:

The which command in terminal returns the following (which is odd because earlier it would return something to just which python):

I gather the error occurs because the terminal calls for python instead of python3, but I am super new to any coding and have no idea why it started now and how to fix it. Nothing of these has worked for me:

• I deleted and then reinstalled python from python.org.
• I tried alias python='python3' (which I saw in one of the threads here).
• I tried export PATH="/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin" (which I found here).
• To reset zsh and paths, I deleted all associated hidden files in /local/users/ and ran the terminal once again.
• I deleted evetyrhing and reinstalled macos and python only to get the same error.

Solution 1

OK, after a couple of days trying, this is what has worked for me:

1. I reinstalled Monterey (not sure it was essential, but I just figured I had messed with terminal and $PATH too much).
2. I installed python via brew rather than from the official website. It would still return command not found error.
3. I ran echo "alias python=/usr/bin/python3" >> ~/.zshrc in terminal to alias python with python3.

Problem solved.

As far as I get it, there is no more pre-installed python 2.x in macOS as of 12.3 hence the error. I still find it odd though that atom-python-run would call for python instead of python3 despite the settings.

Solution 2

Anyone updating their macOS to Monterey 12.3 will find that they suddenly no longer have the system-provided Python 2.

The reason for this is that Apple removed the system-provided Python 2 installation (details).

So a workaround/solution for this is to use pyenv to install Python 2.7 (or any other specific version you need).

1. Install pyenv with brew to manage different Python versions: brew install pyenv
2. List all installable versions with pyenv install --list
3. Install Python 2.7.18 with pyenv install 2.7.18
4. List installed versions with pyenv versions
5. Set global python version with pyenv global 2.7.18
6. Add eval "$(pyenv init --path)" to ~/.zprofile (or ~/.bash_profile or ~/.zshrc, whichever you need)
7. Relaunch the shell and check that Python works.

Solution 3

If you simply installed Python 3, just use python3 as the command instead of just python. In my case, I had to install pynev first via Homebrew (executable brew) using brew install pyenv.

But still after using pynev to install Python 2.7.18 and setting it as a global version using pyenv global 2.7.18, I still ran into an error while trying to run python.

What worked for me (since I already had Python 3 installed) was by changing my command to use python3 instead of just python. Of course, this won't be a solution to everyone who may want to use Python 2.

Comments

[Ava]

In some cases a program that you are using doesn't look into your ~/.zshrc. In my case a more portable solution was to run ln -s /opt/homebrew/bin/python3 /usr/local/bin/python, which doesn't depend on zsh.

[moveson]

This should be the accepted answer if the goal is to get Python 2 working on Mac OS Monterey

[Kambiz]

Why do all answers lead to homebrew? I recently migrated to pyenv + pipenv for management only using macports and I am hitting similar errors. In most cases, the user $PATH is screwed-up.

[Peter Mortensen]

What is "ENVIRONMENT"? Do you mean "environment"? We have italics, bold, and many other formatting options here.

[CheverJohn]

@PeterMortensen I mean that you just add 'alias python=/usr/local/bin/python3.10` into the .zshrc file. That is all.

[MikhailRatner]

Thanks, adding the 3 behind Python made the commands work! I wonder why this is...anyone an explanation?